jamie carter had a consistent advantage over ronald reagan but the final presidential debate changed everything leading to a reagan landslide. now he is building a lead in key battleground states, a consultant who worked for jimmy carter, finding the right sample to survey can be tricky. >> we know from exit polls that republicans tend to respond to these polls less than oftentimes particularly to news organizations less than do democrats. >> reporter: in. >> julie: 8 there was a huge swing. dukakis lost to bush. in 1992 incumbent president was down nine points in mid-september and was tied with bill clinton by the end of october. the clinton eventually won. former clinton pollster is questioning the assumptions being made in today's polls. >> these polls are assuming that you have the same high level of african-american, latino and young people vote in 2012 that you had in 2008. >> obama campaign senior advisor david axelrod said they widely vary so when they all pointed in one direction, they are all wrong. but we are planning for a close race as we always have. another democratic